Sintered porous material comprising particles of different average sizes

Abstract

A porous membrane, comprising a blend of a first powder of metal particles of the first average size and a second powder of metal particles of a second average size, the first powder and the second powder sintered together. The first average size is five to fifty times greater than the second average size. The porous membrane comprises from 40% to 60% by weight of the first powder.

What is claimed is: 
     
       1. A porous membrane, comprising a blend of a first powder of metal particles of a first average size and a second powder of metal particles of a second average size, the first powder and the second powder sintered together,
 wherein the first average size is five to fifty times greater than the second average size, and 
 wherein the porous membrane comprises from 40% to 60% by weight of the first powder, 
 wherein the water bubble point of the porous membrane is from 4 to 8 psi, and 
 wherein the porous membrane has a Log Reduction Value (LRV) of 4 or more for 0.1 micron particles in a gas having velocity of 3 slpm/cm 2  measured on a 0.4 centimeter thick membrane, 
 wherein the first average size is from about 40 microns to about 60 microns, and the second average size is not greater than about 2 microns. 
 
     
     
       2. The porous membrane of  claim 1 , wherein a porosity of the porous membrane is from 37% by volume to 50% by volume. 
     
     
       3. The porous membrane of  claim 1 , wherein a porosity of the porous membrane is from 42% by volume to 48% by volume. 
     
     
       4. The porous membrane of  claim 1 , wherein the first average size is about 50 microns, and the second average size is about 2 microns. 
     
     
       5. The porous membrane of  claim 1 , wherein the metal particles of the first powder and the metal particles of the second powder are each independently selected from nickel or stainless steel. 
     
     
       6. The porous membrane of  claim 1 , wherein the metal particles of the first powder and the metal particles of the second powder are each selected from nickel. 
     
     
       7. A gas diffuser device comprising:
 a housing having an inlet and an outlet; and 
 a porous membrane of  claim 1 . 
 
     
     
       8. The device of  claim 7 , wherein a porosity of the porous membrane is from 37% by volume to 50% by volume. 
     
     
       9. The device of  claim 7 , wherein a porosity of the porous membrane is from 42% by volume to 48% by volume. 
     
     
       10. The device of  claim 7 , wherein the first average size is about 50 microns, and the second average size is about 2 microns. 
     
     
       11. The device of  claim 7 , wherein the metal particles of the first powder and the metal particles of the second powder are each independently selected from nickel or stainless steel. 
     
     
       12. The device of  claim 7 , wherein the metal particles of the first powder and the metal particles of the second powder are each selected from nickel. 
     
     
       13. The device of  claim 7 , wherein the porous membrane is a flat sheet having a thickness of 0.1 inch or more. 
     
     
       14. The device of  claim 7 , wherein the porous membrane is a flat sheet having a thickness from 0.2 cm to 0.5 cm, and further wherein the Log Reduction Value of the porous membrane is at least 6 in a gas for 0.1 micron particles and velocity of 3 slpm/cm 2 . 
     
     
       15. The device of  claim 14 , wherein the porous membrane has a burst pressure of at least 300 pounds per square inch. 
     
     
       16. The device of  claim 14 , wherein the porous membrane has a burst pressure of greater than 350 pounds per square inch. 
     
     
       17. A method of purifying a gas stream, comprising:
 directing a gas stream through a porous membrane of  claim 1 , 
 thereby purifying the gas stream. 
 
     
     
       18. The method of  claim 17 , wherein a porosity of the porous membrane is from 37% by volume to 50% by volume. 
     
     
       19. The method of  claim 17 , wherein a porosity of the porous membrane is from 42% by volume to 48% by volume. 
     
     
       20. The method of  claim 17 , wherein the first average size is about 50 microns, and the second average size is about 2 microns. 
     
     
       21. The method of  claim 17 , wherein the metal particles of the first powder and the metal particles of the second powder are each independently selected from nickel or stainless steel. 
     
     
       22. The method of  claim 17 , wherein the metal particles of the first powder and the metal particles of the second powder are each selected from nickel. 
     
     
       23. The method of  claim 17 , wherein the porous membrane is a flat sheet having a thickness of 0.1 inch or more. 
     
     
       24. The method of  claim 17 , wherein the porous membrane is a flat sheet having a thickness from 0.2 cm to 0.5 cm, and further wherein the Log Reduction Value of the porous membrane is at least 6 in a gas for 0.1 micron particles and velocity of 3 slpm/cm 2 . 
     
     
       25. The method of  claim 24 , wherein the porous membrane has a burst pressure of at least 300 pounds per square inch. 
     
     
       26. The method of  claim 24 , wherein the porous membrane has a burst pressure of greater than 350 pounds per square inch. 
     
     
       27. A gas diffuser device comprising:
 a housing having an inlet and an outlet; and 
 a porous membrane of  claim 1  disposed within the housing in fluid communication with the inlet and the outlet, 
 wherein the porous membrane is a flat sheet having a thickness from 0.2 cm to 0.5 cm, having Log Reduction Value of at least 6 in a gas for 0.1 micron particles and velocity of 3 slpm/cm 2 , and a burst pressure of at least 300 pounds per square inch